The present invention relates generally to transmission electron microscopy, and more specifically, to transmission electron microscopy analyzing a sample using two low-voltage electron beams.
Electron microscopy provides an electron beam to a sample to analyze characteristics of the sample. Relatively high-energy electrons, such as between 10-20 keV may be emitted from an electron gun. The electrons travel through a condenser and an objective lens and are slowed by a sample bias or potential. At the surface of the sample, the electrons may have a low energy level, such as between near 0 eV-100 eV, and may interact with the surface of the sample and in a region within the sample that is close to the surface. The electrons backscatter and re-accelerate to the relatively high-energy level. The electrons may be projected onto an imaging plane, and patterns generated by the electrons may provide information regarding the sample, and in particular regarding a surface region of the sample.